Daylily Dictionary

Use any of the sub-terms below as a search criteria to filter daylilies that you are interested in. 


Diploid—A daylily with the typical 22 chromosomes.

Tetraploid—A daylily with 44 chromosomes, twice the typical number. Tetraploid daylilies have larger and thicker leaves and flowers, stronger flower scapes, more intense coloration, and increased vigor.


Single—Daylily flowers that usually have three petals, three sepals, six stamens and one pistil (comprised of three carpels).

Double—There are two main forms of Double daylilies. ‘Hose-in-Hose’ doubles have extra whorls (layers) of petals so that there appears to be a flower within a flower. ‘Peony type’ doubles have petaloid (petal-like) stamens inside the normal petal whorl.

Spider—A flower whose petals have a length-to-width ratio of at least 4 to 1 (i.e., 4:1).

Bloom Habit

Diurnal—a daylily that blooms during the day or in the early morning.

Extended—a daylily whose bloom remains open for at least 16 hours.

Nocturnal—a daylily that blooms late in the afternoon and stays open until the morning.


Dormant—Dormant means deciduous. Dormant daylilies lose their foliage completely when frost arrives in the fall.

Semi-Evergreen—A semi-evergreen daylily is a daylily that has foliage that is in between evergreen and dormant in the winter.

Evergreen—Evergreen daylilies are a type of daylily that can grow in areas that don't experience freezing temperatures in the winter.


Short—Daylilies that typically grow to only 20 inches or less.

Medium—Daylilies that grow greater than 20 inches, but less than 30 inches.

Tall—Daylilies that typically grow 30 inches or taller.

Bloom Size

Miniature—Blooms that are less than 3 inches diameter.

Small—3 inches to less than 4.5 inches in diameter.

Large—4.5 inches to less than 7 inches in diameter.

Extra Large—7 inches or larger.